1. Department of Chemistry and Biochemistry, Bradley University, Peoria, Illinois 61625, Crop Bioprotection Research Unit, USDA, ARS, MWA, National Center for Agricultural Utilization Research, 1815 North University Street, Peoria, Illinois 61604, and Plant Polymer Research Unit, **USDA, ARS, MWA, National Center for Agricultural Utilization Research, 1815 North University Street, Peoria, Illinois 61604